We compared a range of anatomical features of northern leopard frogs (Rana pipiens Schreber) collected from areas where deformity rates were low (-2% in nonstressed regions) and high (-40% in the stressed region) to determine if one or more of these characters might be useful in detecting developmen...

The negative impact of brown-headed cowbird parasitism (Molothrus ater) on the reproductive success of many songbirds has led to the evolution of host defensive behaviours that may reduce the chance of being parasitized. Populations of songbirds that have only recently experienced cowbird parasitism...

Using information from published studies, the relative sensitivity of various freshwater fish to a range of chemicals was examined. Specifically, the objectives were to: (1) determine which species are used most often in toxicity tests, (2) assess the relative sensitivity of these species to various...

Japanese medaka (Oryzias latipes) were exposed to octylphenol, a known oestrogen agonist, to assess its effects on reproductive success. Male and female medaka were exposed to nominal concentrations of 10, 25, 50, and 100 micro g/litre octylphenol from 1 day after hatching to 6 months after hatching...

We exposed Japanese medaka (Oryzias latipes) to environmentally relevant concentrations of azinphos-methyl, chlorothalonil, endosulfan, and mixtures of all three to determine if combinations of these pesticides result in additive, less-than-additive, or more-than-additive effects. Medaka were expose...

Exposure of Japanese medaka (O. latipes) embryos and adult males to sublethal concentrations of two commonly used fungicides, Acrobat MZ (a.i. are dimethomorph and mancozeb) and Tattoo C (a.i. are propanocarb and chlorothalonil) had varying effects on the development and adult male behaviour. During...

The cause of size differences among developing fish is often not clear. We examined variability in egg size and in incubation time to determine whether either influenced hatching size or initial rates of growth in Japanese Medaka. We also tested the prediction that larger females should produce heav...

Estuarine eutrophication as a result of agricultural land use, including the use of chemical fertilizers, is increasing worldwide. Prince Edward Island (PEI), Canada has very high agricultural intensity by international standards with approximately 44% of the land area under production, and some wat...

The freshwater sports fishery of Prince Edward Island (PEI) revolves largely around three salmonid species—Salvelinus fontinalis (Brook Trout), Salmo salar (Atlantic Salmon), and the nonnative Oncorhynchus mykiss (Rainbow Trout). However, little is known about their current distribution and relati...

Two agricultural runoff events involving the pesticide azinphos-methyl occurred in July 2002 on the Wilmot River, Prince Edward Island, Canada, resulting in the death of thousands of fish. The fish communities from three sites on this river had been sampled in 2001, permitting comparisons of brook t...

The use of multiple spawning fishes in environmental effects monitoring programs has proven difficult for a number of reasons including the inability to predict reproductive investment and ensure synchronous sampling of reference and impacted populations. The estuarine resident northern mummichog (F...

We surveyed 11 forest remnants and their adjacent ponds to assess the species richness of amphibians on Prince Edward Island, Canada. By combining aquatic and terrestrial sampling methods, we detected the presence of four urodeles and five anurans in our study sites. No significant difference in spe...

Artificial fertilizers are contributing to the replacement of eelgrass (Zostera marina) by sea lettuce (Ulva lactuca) in estuaries of Prince Edward Island (PEI), Canada. In this study, we found that the nearshore fish community differed between areas dominated by these two vegetations within an estu...

Chytridiomycosis, caused by the fungus Batrachochybium dendrobatidis (Bd), has resulted in the decline or extinction of approximately 200 frog species worldwide. It has been reported throughout much of North America, but its presence on Prince Edward Island (PEI), on the eastern coast of Canada, was...